Improved saw-file



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A liu/675601@ '"PETN PHOTO-LITHOGRAPHER. WASHINGTON D C llntd ltere @stent @Mira WILLIAM ROBERTS, OF BLUE HILL, MAINE.

Letters `Patent No. $20,784, dated .Tu-ne '1, 1869.

IMPROVED SAW-FILE.

The Schedule referred to in these Letters Patent and making part of the lama.

,the accompanying drawings, forming .part of this speciflication, in which is shown a side view of my invention at A, and a section at B. v

The purpose of my invention is to produce a file, by the use of which saws can be more easily, quickly, and regularly led and sharpened than by the useof the common file, or one not specially designed for this particular purpose.

In ling saws with the le 'inordinary use, it is necessary to file each side of a given Ytooth separately, and the evenness and regularity of the strok'e are; of course, not at all times under the control of the operator. Moreover, by reason of the shape of the tool,

and the fact that it is regulated solely by the hand of the operator, the attrition is quite variable.

My invention seeks to obviate these objections, by

- producing a le of such construction as will enable the user to le with more rapidity, and make the cuttings the same throughout.

I effect this by giving the file-blade theshapeshown in the d1awings,more particularly in the section at- B. 'lhe file-blade is' thickest at the centre thereof, and the two faces on the same side of this thickest portion are inclined to each other, till they meet at the edges. It will be observed that these inclined faces will lill a space similar in shape to the spaces between the teeth of a saw.

Thus the operator is enabled, at the same time, to

file and sharpen both the front edge of one tooth and the rear of the next successive one.

Regularity in the spaces between tbe teeth,`and in the shape of the same, as well as uniformity in the cutting-edges, is attained by this invention.

The size, depth, and exact shape of the spaces can l all be regulated by the size of the tool and the inclination of its sides.

Two sets of cutting-sides being furnished, to wit, `1 and 2when one is worn, the other can be employed. The cutting-edges, or corrugations on the sides are drawn diagonally, so as to aiord betterfacilities for removing the shavings, or filings fromthe teethof the saw, by making a drawing cut, and to prevent shak ing or vibration of the teeth, while submitted to the operation of the tool.

Still further, the body of the file-blade is larger in the middle of its length, or grows larger as you approach the handle thereof.

Now, the inclined cutting-edges, or corrugations, by their direction, tend to keep the iile down in the spaces between the teeth, and, by' the forward motion ofthe tool, the larger part being forced into the said spaces, of course the cutting-power is increased, by the combination of said diagonal lines and the said increasing thickness of the blade.

What I claim as my invention, and desire to secure by Letters Patent, is

The improved saw-file, made as described, and combining the features herein set forth, for the purposes specified.

` WgILLIAM ROBERTS. yWitnesses:

JOHN A. STEvENs, AUGUSTUS STEVENS 

